gdata: Fix "save as pdf" to work on Google Drive.

chrome/browser/chromeos/gdata/gdata_file_system.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/chromeos/gdata/gdata_file_system.h"
 
 #include <set>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 4150 matching lines @@
   // All the invocation of |callback| from operations initiated from CloseFile
   // must go through here. Removes the |file_path| from the remembered set so
   // that subsequent operations can open the file again.
   open_files_.erase(file_path);
 
   // Then invokes the user-supplied callback function.
   if (!callback.is_null())
     callback.Run(result);
 }
 
+void GDataFileSystem::PrepareWritableFileAndRun(
+    const FilePath& file_path,
+    const OpenFileCallback& callback) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI) ||
+         BrowserThread::CurrentlyOn(BrowserThread::IO));
+  RunTaskOnUIThread(
+      base::Bind(&GDataFileSystem::PrepareWritableFileAndRunOnUIThread,
+                 ui_weak_ptr_,
+                 file_path,
+                 callback));
+}
+
+void GDataFileSystem::PrepareWritableFileAndRunOnUIThread(
+    const FilePath& file_path,
+    const OpenFileCallback& callback) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  CreateFileOnUIThread(
+      file_path,
+      false, // it is not an error, even if the path already exists.
+      base::Bind(&GDataFileSystem::PrepareWritableFileAndRunAfterCreateFile,
+                 ui_weak_ptr_,
+                 file_path,
+                 callback));
+}
+
+void GDataFileSystem::PrepareWritableFileAndRunAfterCreateFile(
+    const FilePath& file_path,
+    const OpenFileCallback& callback,
+    GDataFileError result) {

[satorux1, 2012/07/27 22:56:29]

result -> error

[kinaba, 2012/08/01 13:48:45]

Done.

+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  if (result != gdata::GDATA_FILE_OK) {
+    if (!callback.is_null()) {
+      content::BrowserThread::GetBlockingPool()->PostTask(
+          FROM_HERE,
+          base::Bind(callback, result, FilePath()));

[satorux1, 2012/07/27 22:56:29]

we should just run the callback here.

PostTask should rarely be used. Maybe we should check and fix the existing
usage. I'll file a bug.

[kinaba, 2012/08/01 13:48:45]

This is not a PostTask to the current thread, it is posting to blocking thread
pool (since |callback| needs to be called on that thread in successful cases,
I'd like to align the failure case to it.)

+    }
+    return;
+  }
+  OpenFileOnUIThread(
+      file_path,
+      base::Bind(&GDataFileSystem::PrepareWritableFileAndRunAfterOpenFile,
+                 ui_weak_ptr_,
+                 file_path,
+                 callback));
+}
+
+void GDataFileSystem::PrepareWritableFileAndRunAfterOpenFile(
+    const FilePath& file_path,
+    const OpenFileCallback& callback,
+    GDataFileError result,

[satorux1, 2012/07/27 22:56:29]

error

[kinaba, 2012/08/01 13:48:45]

Done.

+    const FilePath& local_cache_path) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  if (result != gdata::GDATA_FILE_OK) {
+    if (!callback.is_null()) {
+      content::BrowserThread::GetBlockingPool()->PostTask(

[satorux1, 2012/07/27 22:56:29]

ditto

[kinaba, 2012/08/01 13:48:45]

See the reply above.

+          FROM_HERE,
+          base::Bind(callback, result, FilePath()));
+    }
+    return;
+  }
+
+  if (!callback.is_null()) {
+    content::BrowserThread::GetBlockingPool()->PostTaskAndReply(
+        FROM_HERE,
+        base::Bind(callback, GDATA_FILE_OK, local_cache_path),
+        base::Bind(&GDataFileSystem::PrepareWritableFileAndRunAfterCallback,
+                   ui_weak_ptr_,
+                   file_path));
+  } else {
+    PrepareWritableFileAndRunAfterCallback(file_path);
+  }
+}
+
+void GDataFileSystem::PrepareWritableFileAndRunAfterCallback(
+    const FilePath& file_path) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  CloseFileOnUIThread(file_path, FileOperationCallback());
+}
+
 }  // namespace gdata